Avalanche: Superior

Our party of two crested the summit of Superior and proceeded to work slowly down the upper ridge two or three notches to enter the upper south face just downslope of numerous tracks from earlier in the day. Wind activity had become more severe approaching the top, and was sufficient to push out the cloud cover that had obscured the peak in the early morning. Familiar with the wind-drifted avalanche problem that had been presenting itself on Superior/Little over the last few days, we assessed the risk/reward of skiing just beyond the zone where the slope had been tested earlier in the morning. The first skier in the party entered the face making turns cautiously given the risk of shallow instability, and triggered a soft slab avalanche approximately 60' wide and 15" deep at his feet on the steeper S/SE aspect of the slope where the rocky ridgeline spines meet the upper snowfield. The skier was carried to the mouth of the rider's right choke before coming to a stop on top of the avalanche debris. Having seen the carried skier come to a stop atop the debris, I proceeded to ski to his position without any further issues on that aspect.

Given the strength of the winds midday into the afternoon, it appears that sizable quantities of snow have been transported onto/across Superior's (upper) South Face, possibly magnifying the wind slab problem that was causing smaller, more isolated chunks to break free at upper elevations on this S/SE aspect. We were fortunate that the slab didn't run further, possibly carrying the skier through the rocky choke above the face's lower apron. The skier was uninjured.